Heat dissipation apparatus

ABSTRACT

An exemplary heat dissipation apparatus includes a first heat spreader, a second heat spreader, a fixing member, an elastic member, a heat sink, a first heat pipe, a second heat pipe, and a fan. The fixing member includes a first fixing plate, and a second fixing plate connected to the second heat spreader. The elastic member includes a fixing piece fixedly joined to the first heat spreader, and a latching piece extending from each end of the fixing piece and movably connected to the first fixing plate. The first heat spreader can move with the latching piece toward or away from the first fixing member. The fan defines an air outlet facing the heat sink. Two ends of the first heat pipe respectively contact the first heat spreader and the heat sink. Two ends of the second heat pipe contact the second heat spreader and the heat sink, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to a co-pending application entitled as “THERMAL MODULE”, assigned to the same assignee of this application and filed on the same date. The disclosure of the co-pending application is wholly incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates generally to heat dissipation apparatuses, and more particularly to a heat dissipation apparatus which can cool plural electronic components of an electronic device simultaneously.

2. Description of Related Art

With the continuing development of electronics technology, electronic components of electronic devices, such as central processing units (CPUs), memory modules, and video graphics array (VGA) chips, feature increasingly high operating speeds. Accordingly, these electronic components generate much heat, which needs to be dissipated immediately to ensure the continued proper functioning of the electronic device.

Generally, a heat sink is mounted onto the CPU of an electronic device to absorb heat therefrom, and a fan is provided to generate airflow to take away the heat of the heat sink. The air after having crossed the heat sink is heated, and such air cannot efficiently cool VGA chips, memory modules and other electronic components located around the CPU. Yet many modern electronic devices, particularly portable electronic devices such as notebook computers, game players and the like, are very compact and light. Such portable electronic devices typically do not provide enough space for installing a heat sink onto each electronic component thereof.

What is needed, therefore, is a heat dissipation apparatus to overcome the above-described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, assembled view of a heat dissipation apparatus, according to an exemplary embodiment.

FIG. 2 is an exploded view of FIG. 1.

FIG. 3 is an enlarged view of an elastic member of the heat dissipation apparatus shown in FIG. 2.

FIG. 4 is an enlarged view of a fixing plate of the heat dissipation apparatus shown in FIG. 2.

FIG. 5 is a cross-sectional view of FIG. 4, taken along line V-V thereof.

FIG. 6 is an enlarged view of a fastener of the heat dissipation apparatus shown in FIG. 2.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a heat dissipation apparatus 10 according to an exemplary embodiment is shown. The heat dissipation apparatus 10 includes a first heat spreader 11, a second heat spreader 12, a fixing member 13, a heat sink 15, a first heat pipe 16, two second heat pipes 17, and a centrifugal fan 18.

The first heat spreader 11 is made of metal or metal alloy which has a high heat conductivity coefficient, such as copper or copper-alloy. The first heat spreader 11 is rectangular and flat. The first heat spreader 11 includes a planar bottom face 110 configured for contacting a heat generating component (not shown), and a planar top face 112. The heat generating component is typically an electronic component. Two elastic members 19 are fixedly joined to the top face 112 of the first heat spreader 11. The two elastic members 19 are arranged parallel to each other, and are spaced from each other. Each elastic member 19 is formed by bending a narrow metal sheet.

The two elastic members 19 are identical to each other. Referring also to FIG. 3, each elastic member 19 includes a fixing piece 190, and two latching pieces 192 bending from opposite ends of the fixing piece 190, respectively. The fixing piece 190 is fixed on the top face 112 of the first heat spreader 11. A middle of the fixing piece 190 protrudes upwards to form a bridge 191. In this embodiment, the bridge 191 includes two connecting portions 195 extending perpendicularly from the fixing piece 190, and a resisting portion 193 interconnecting top ends of the connecting portions 195. The resisting portion 193 is parallel to, and is spaced apart from, the fixing piece 190. A space 100 is thus formed between the resisting portion 193 and the first heat spreader 11, for receiving the first heat pipe 16.

Each of the latching pieces 192 includes an elongated portion 194 and a latching portion 196. The two elongated portions 194 of the latching pieces 192 are straight, and extend aslant from opposite ends of the fixing piece 190 generally towards each other. The latching portions 196 of the latching pieces 192 are respectively formed at top ends of the elongated portions 194, and are configured like a pair of symmetrically opposite angle brackets. More specifically, each latching portion 196 is generally V-shaped, and includes a first section 197 bending outward and upwardly from the elongated portion 194 generally away from the other latching portion 196, and a second section 198 bending inward and upwardly from the first section 197 generally towards the other latching portion 196. Thus a distance between the two junctions of the latching portions 196 and the elongated portions 194 is smaller than that between the first sections 197 of the latching portions 196.

Referring to FIG. 2 again, the second heat spreader 12 is also made of metal or metal alloy which has a high heat conductivity coefficient. The second heat spreader 12 is rectangular; and includes a planar bottom surface 124 configured for contacting another heat generating component (not shown), and a top surface 126. Two upper grooves 120 are defined in the top surface 126 of the second heat spreader 12. The upper grooves 120 are straight and parallel to each other. Each upper groove 120 extends through the second heat spreader 12 along a longitudinal direction of the second heat spreader 12. A cross section of each of the upper grooves 120 is semicircular. A securing portion 121 extends outwards from each lateral side of the second heat spreader 12. Two securing holes 122 are defined in each of the securing portions 121.

The fixing member 13 is also made of metal or metal alloy which has a high heat conductivity coefficient, such as aluminum or aluminum-alloy. The fixing member 13 is integrally formed as a single monolithic piece. The fixing member 13 includes a first fixing plate 130 mounted on the first heat spreader 11, a second fixing plate 140 mounted on the second heat spreader 12, and a connecting plate 131 interconnecting the first fixing plate 130 and the second fixing plate 140.

The first fixing plate 130 defines two slots 133 corresponding to the elastic members 19. The slots 133 are elongated, and are parallel to each other. Each slot 133 extends through the first fixing plate 130 along the thickness direction of the first fixing plate 130. A length of the slot 133 is shorter than the distance between the junctions of the latching portions 196 and the elongated portions 194 of the latching pieces 192 when the latching pieces 192 are in a free state. Referring also to FIGS. 4 and 5, a protrusion 136 extends from the first fixing plate 130 into the slot 133 at each end of the slot 133. A profile of a cross section of the protrusion 136 is generally V-shaped. The protrusion 136 includes a first outer side 137 a and a second outer side 137 b extending aslant from the end of the slot 133, with the first and second outer sides 137 a, 137 b meeting at an apex of the V-shape.

Referring back to FIG. 1 again, when the heat dissipation apparatus 10 is assembled, the first fixing plate 130 of the fixing member 13 is arranged over the first heat spreader 11 such that the slots 133 are aligned with the elastic members 19. A force is applied to the latching pieces 192 of each elastic member 19 to decrease the distance between the latching pieces 192, thus the latching portions 196 of each elastic member 19 can extend through the corresponding slot 133 of the first fixing plate 130. Therefore, the protrusions 136 of the first fixing plate 130 are engaged with the junctions of the elongated portions 194 and the latching portions 196 of the latching pieces 192 to avoid disengagement of the elastic members 19 from the first fixing plate 130. Thus the first heat spreader 11 is connected to the first fixing plate 130 of the fixing member 13, as shown in FIG. 1.

It should be understood that the elastic members 19 engaged in the slots 133 of the first fixing plate 130 are not fixed, and thus can be further pushed to move upwardly. Accordingly, the first heat spreader 11 fixed with the elastic members 19 can move upwardly with the elastic members 19 towards the first fixing plate 130, thereby reducing a distance between the first heat spreader 11 and the first fixing plate 130. Therefore, when the heat dissipation apparatus 10 is applied to an electronic device with a shallow space above the heat generating component, the elastic members 19 can be pushed towards the first fixing member 130 to adjust the distance between the first heat spreader 11 and the first fixing plate 130. Thus the first heat spreader 11 can be accurately and intimately mounted onto the heat generating component to absorb heat therefrom. In such a state, pressure of the first heat spreader 11 keeps the elastic members 19 stably engaged with the first fixing plate 130 at middle sections of the elongated portions 194. That is, the first fixing plate 130 is held in position closer to the first heat spreader 11 than is shown in FIG. 1.

Referring to FIG. 2 again, the second fixing plate 140 is rectangular, and has a size the same as that of the second heat spreader 12. Two lower grooves 143 are formed at a bottom of the second fixing plate 140, corresponding to the upper grooves 120 of the second heat spreader 12. A cross section of each lower groove 143 is semicircular. When assembled, the second fixing plate 140 is disposed on the second heat spreader 12 such that the lower grooves 143 are aligned with the upper grooves 120. Screws (not shown) extend through the securing holes 122 of the second heat spreader 12 and are engaged in the second fixing plate 140. In this way, the second heat spreader 12 is attached to the fixing member 13. Thus, each upper groove 120 and one corresponding lower groove 143 together form a cylindrical channel for receiving one second heat pipe 17.

Four fixing portions 142 extend outwards from four corners of the second fixing plate 140, respectively. A fixing hole 144 is defined in an outer end of each fixing portion 142, for assembling of the fixing member 13 to one or more electronic components. A supporting plate 145 is connected between outer ends of two of the fixing portions 142 which are farthest away from the first fixing plate 130. An ear 132 extends integrally outward from the connecting plate 131 at a position near the first fixing plate 130. A circular hole 138 is defined in the ear 132. An opening 139 is defined in the ear 132 at a side facing the first fixing plate 130. The opening 139 communicates the circular hole 138 with the outside. A width of the opening 139 is slightly narrower than a diameter of the circular hole 138.

The heat sink 15 is arranged on the supporting plate 145 of the fixing member 13, and includes a plurality of fins 150 spacedly stacked in parallel along a longitudinal direction of the supporting plate 145. Three channels 152 extend through the heat sink 15 for receiving the first heat pipe 16 and the second heat pipes 17. A tab 153 extends from a corner of each outmost fin 150 of the heat sink 15 towards the second fixing plate 140. Each of the tabs 153 is parallel to each of the fins 150 of the heat sink 15. A through hole 154 is defined in each tab 153. An aperture 155 is defined in each tab 153 for communicating the through hole 154 with the outside. A width of the aperture 155 is slightly narrower than a diameter of the through hole 154. Preferably, the diameter of the through hole 154 is equal to that of the circular hole 138 of the ear 132, and the width of the aperture 155 is equal to that of the opening 139 of the ear 132.

The first heat pipe 16 includes an evaporation section 160 and a condensing section 162 respectively formed at opposite ends thereof. Each of the second heat pipes 17 includes an evaporation section 170 and a condensing section 172 respectively formed at opposite ends thereof. The evaporation section 160 of the first heat pipe 16 is received in the space 100 formed between the bridge 191 of the elastic members 19 and the first heat spreader 11, while the condensing section 162 of the first heat pipe 16 is received in one of the channels 152 of the heat sink 15. The evaporation sections 170 of the second heat pipes 17 are respectively received in the cylindrical channels formed by the upper grooves 120 of the second heat spreader 12 and the lower grooves 143 of the second fixing plate 140. The condensing sections 172 of the second heat pipes 17 are respectively received in the other two channels 152 of the heat sink 15. Thus the heat sink 15, the first heat pipe 16, the second heat pipes 17, the first heat spreader 11, the second heat spreader 12, and the fixing member 13 are connected together.

The centrifugal fan 18 is slidably mounted on the second fixing plate 140 of the fixing member 13 by three fasteners 20. The fasteners 20 are made of rubber, and are elastic. Referring also to FIG. 6, each fastener 20 includes a head 21, and a pole 22 smaller than the head 21 in diameter. An annular notch 23 is defined in the head 21 of the fastener 20. The diameter of the head 21 at the annular notch 23 is slightly larger than the widths of the opening 139 of the ear 132 and the apertures 155 of the tabs 153, but not larger than the diameters of the circular hole 138 and the through holes 154. A locking portion 24 protrudes outwards from the pole 22 of the fastener 20 at a position adjacent to the head 21. An outer surface 242 of the locking portion 24 converges along the longitudinal direction of the head 21 from an end adjacent to the head 21 to an opposite end away from the head 21. Part of the outer surface 242 of the locking portion 24 is cut to form two opposite flat surfaces 240, for facilitating assembly of the fastener 20 to the centrifugal fan 18.

The centrifugal fan 18 includes a housing 180, and an impeller 182 rotatably received in the housing 180. An air outlet 183 is defined in the housing 180 and faces the heat sink 15, thereby airflow generated by the centrifugal fan 18 can directly flow to the heat sink 15. Two sliding members 184 extend outwards from the housing 180 at opposite ends of the air outlet 183 towards the heat sink 15. The sliding members 184 are elongated, and parallel to the fins 150 of the heat sink 15. A distance between the sliding members 184 is slightly larger than a distance between the tabs 153 of the heat sink 15. A sliding groove 185 is defined in each of the sliding members 184. Each sliding member 184 is elongated, with a length thereof much greater than a width thereof. Preferably, the width of the sliding groove 185 is slightly greater than the diameter of the pole 22 of the corresponding fastener 20, but slightly less than a minimum width of the locking portion 24 of the fastener 20.

A mounting portion 186 extends outwards from the housing 180, corresponding to the ear 132 of the fixing member 13. In this embodiment, the two sliding members 184 are arranged symmetrically about an axis (not shown) defined by the mounting portion 186. A mounting hole 187 is defined in the mounting portion 186, corresponding to the circular hole 138 of the ear 132. Preferably, a diameter of the mounting hole 187 is equal to the width of the sliding groove 185 of the sliding member 184. That is, the diameter of the mounting hole 187 is greater than the diameter of the pole 22 of the corresponding fastener 20, but slightly less than the minimum width of the locking portion 24 of the fastener 20.

When assembling the fasteners 20 to the centrifugal fan 18, the locking portions 24 of the fasteners 20 are extruded to decrease the widths thereof, and thus can be extended through the sliding grooves 185 of the sliding members 184 and the mounting hole 187 of the mounting portion 186, respectively. Thus, the fasteners 20 are assembled on the centrifugal fan 18, with the mounting portion 186 and the sliding members 184 engaged between the heads 21 and the locking portions 24 of the respective fasteners 20. Since the sliding grooves 185 are elongated, the poles 22 of the two fasteners 20 on the sliding members 184 can slide along the sliding grooves 185. In this embodiment, after being assembled, the heads 21 of the two fasteners 20 engaged with the sliding members 184 are located between the sliding members 184, and the head 21 of the fastener 20 engaged with the mounting portion 186 is below the mounting portion 186.

The centrifugal fan 18 with the fasteners 20 is then mounted onto the second fixing plate 140 of the fixing member 13 such that the annular notches 23 of the heads 21 of the fasteners 20 on the sliding members 184 are aligned with the apertures 155 of the tabs 153. The heads 21 of the two fasteners 20 are respectively pushed into the circular holes 138 via the apertures 155. Since the diameters of the two fasteners 20 at the annular notches 23 are larger than the widths of the apertures 155, the fasteners 20 are fixedly engaged in the through holes 154 of the tabs 153 of the heat sink 15. That is, the components of the heat dissipation apparatus 10, i.e., the centrifugal fan 18, the heat sink 15, the first heat pipe 16, the second heat pipes 17, the first heat spreader 11, the second heat spreader 12 and the fixing member 13 are connected together.

For facilitating assembly of the heat dissipation apparatus 10 to the electronic components, the centrifugal fan 18 is kept at a position in which the poles 22 of the fasteners 20 on the sliding members 184 are located at outmost ends of the sliding grooves 185, to expose the fixing holes 144. Accordingly, in such a state, the head 21 of the fastener 20 on the mounting portion 186 is at a lateral side of the ear 132 of the fixing member 13, and faces the opening 139. Screws (not shown) are extended through the four fixing holes 144 of the fixing member 13 to engage with a circuit board on which the electronic components are arranged. Then the centrifugal fan 18 is pushed to slide towards the heat sink 15, and thus cause the head 21 of the fastener 20 on the mounting portion 186 to engage in the circular hole 138 of the ear 132 via the opening 139. Thereby, the stability of the centrifugal fan 18 is enhanced. Thus the first heat spreader 11 and the second heat spreader 12 of the heat dissipation apparatus 10 are mounted on two different electronic components. As shown in FIG. 1, in such a state, the heat sink 15 is adjacent to the air outlet 183 of the centrifugal fan 18, the two fasteners 20 on the sliding members 184 are located adjacent to the air outlet 183 of the centrifugal fan 18, and two of the fixing holes 144 which are farthest away from the first fixing plate 130 are located under and shaded by the centrifugal fan 18.

When the heat dissipation apparatus 10 is used in a typical application, the first heat spreader 11 and the second heat spreader 12 absorb heat from the two different electronic components, such as a memory module and a CPU. The heat of the first heat spreader 11 and the second heat spreader 12 is then timely transferred to the heat sink 15 by the first heat pipe 16 and the second heat pipes 17, and finally is taken away to the outside by the airflow of the centrifugal fan 18. Therefore, the heat dissipation apparatus 10 can take away the heat from the two electronic components simultaneously. In addition, since the distance between the first heat spreader 11 and the first fixing plate 130 is adjustable, the electronic component on which the first heat spreader 11 is arranged can have any of various different heights. Therefore, even if the two electronic components are not at the same level, the heat dissipation apparatus 10 can still be intimately attached to both the electronic components. Accordingly, a space needed for accommodating the heat dissipation apparatus 10 can be significantly reduced, and a size of the electronic device can correspondingly be significantly reduced.

It is to be understood, however, that even though numerous characteristics and advantages of certain embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A heat dissipation apparatus, comprising: a first heat spreader configured for contacting one heat generating component; a second heat spreader configured for contacting another heat generating component; a fixing member comprising a first fixing plate mounted on the first heat spreader and a second fixing plate connected to the second heat spreader; and an elastic member interconnecting the first heat spreader and the first fixing plate, wherein the elastic member is adjustably connected to the first fixing plate.
 2. The heat dissipation apparatus of claim 1, wherein the elastic member comprises a fixing piece fixedly joined to the first heat spreader and two elastic latching pieces respectively extending from opposite ends of the fixing piece through the first fixing plate.
 3. The heat dissipation apparatus of claim 2, wherein the elastic member is in the form of a bent narrow metal sheet.
 4. The heat dissipation apparatus of claim 2, wherein each latching piece comprises an elongated portion extending aslant from the fixing piece generally towards the other latching piece and a V-shaped latching portion formed at an end of the elongated portion farthest away from the fixing piece.
 5. The heat dissipation apparatus of claim 4, wherein each latching portion comprises a first section bending outward and upwardly from the elongated portion generally away from the other latching portion, and a second section bending inward and upwardly from the first section generally towards the other latching portion.
 6. The heat dissipation apparatus of claim 4, wherein the first fixing plate defines a slot, the latching pieces of the elastic member extending through the slot, a length of the slot being smaller than a distance between a joint of the elongated portion and the latching portion of one of the latching pieces and a joint of the elongated portion and the latching portion of the other latching piece when the elastic member is in a free state.
 7. The heat dissipation apparatus of claim 6, wherein the first fixing plate comprises two protrusions extending from each end of the slot into the slot for engaging with the joints of the elongated portion and the latching portion of the corresponding latching pieces, each of the protrusions comprising two outer sides extending aslant from a main body of the first fixing plate and meeting at an apex.
 8. The heat dissipation apparatus of claim 4, wherein a middle of the fixing piece comprises a bridge protruding outwards from other portions of the fixing piece, and a space is thereby formed between the bridge and the first heat spreader for receiving a heat pipe.
 9. The heat dissipation apparatus of claim 1, wherein a plurality of fixing portions extend outwards from the second heat spreader, each fixing portion defining a fixing hole for assembling the fixing member to one or more electronic components.
 10. The heat dissipation apparatus of claim 9, wherein the second heat spreader is fixedly connected to the second fixing plate, and a receiving groove is defined between the second heat spreader and the second fixing plate for receiving a heat pipe.
 11. The heat dissipation apparatus of claim 9, wherein a supporting plate is formed between two of the fixing portions which are farthest away from the first fixing plate, for supporting a heat sink thereon.
 12. The heat dissipation apparatus of claim 9, further comprising a fan slidably arranged on the second fixing plate, at least one of the fixing holes located under the fan.
 13. A heat dissipation apparatus, comprising: a first heat spreader configured for contacting one heat generating component; a second heat spreader configured for contacting another heat generating component; a fixing member comprising a first fixing plate, and a second fixing plate connected to the second heat spreader; an elastic member comprising a fixing piece fixedly joined to the first heat spreader and a pair of elastic latching pieces extending from opposite ends of the fixing piece, the latching pieces being movably connected to the first fixing plate such that the first heat spreader is movable toward or away from the first fixing member to a position that is a desired distance from the first fixing member; a fan arranged on the second fixing plate, the fan comprising an air outlet; a heat sink arranged at the air outlet of the fan; a first heat pipe comprising a first evaporating section contacting the first heat spreader, and a first condensing section contacting the heat sink; and a second heat pipe comprising a second evaporating section contacting the second heat spreader, and a second condensing section contacting the heat sink.
 14. The heat dissipation apparatus of claim 13, wherein a bridge protrudes outwards from a middle of the fixing piece towards the first fixing plate, a space being formed between the bridge and the first heat spreader receiving the first evaporation section of the first heat pipe therein.
 15. The heat dissipation apparatus of claim 14, wherein each latching piece comprises an elongated portion extending aslant from the fixing piece towards the other latching piece, and a V-shaped latching portion formed at an end of the elongated portion away from the fixing piece, the latching portions of the elastic member being arranged like a pair of symmetrically opposite angle brackets.
 16. The heat dissipation apparatus of claim 15, wherein the first fixing plate defines a slot for extension of the latching pieces of the elastic member, a length of the slot being smaller than a distance between joints of the elongated portions and the latching portions when the elastic member is in a free state.
 17. The heat dissipation apparatus of claim 16, wherein a protrusion extends from each end of the slot into the slot for engaging with the joint of the elongated portion and the latching portion of the corresponding latching piece, the protrusion comprising two outer sides extending aslant from the end of the slot to joint with each other.
 18. The heat dissipation apparatus of claim 13, wherein a plurality of fixing portions extend outwards from the second heat spreader, a fixing hole is defined in each fixing portion for assembling the fixing member to the electronic components, at least one of the fixing holes being located under the fan.
 19. The heat dissipation apparatus of claim 18, wherein the fan is a centrifugal fan.
 20. The heat dissipation apparatus of claim 18, wherein a supporting plate is formed between two fixing portions which are farthest away from the first fixing plate, and the heat sink is arranged on the supporting plate. 